Section 5: Overhead Signs

Introduction

High-speed, high-volume highways depend on fully effective
overhead signs. Therefore, it is essential that overhead signs be
properly maintained at all times.

Except for supports, overhead signs should require less maintenance
than ground mounted signs. This is a result of their mounting height
and the materials the overhead signs are made of. Damage by vandalism
is also less. However, when damage does occur, immediate measures
should be taken to repair the damage if sign effectiveness is impaired.
Most damage to overhead signs is caused by thrown objects and firearms,
usually resulting in minor damage.

Special Equipment

Supports

All overhead sign supports should be thoroughly inspected
every two years for actual or probable structural distress or failure.
Possible causes of distress and failure include overload fatigue,
corrosion, vandalism, and collision damage. Components to be examined
include: